[Lowfer] E probes .v. loops

Thu, 11 Sep 2003 12:05:09 -0400

Laurence

Here's another 2 cents...

Same e probe antenna, same HP3586C, same installation techniques (ground
mounted) - three different sites. Noise floor  measured in a 3100 Hz bandwidth
is as follows:

at home (rural neighborhood) -88 to -94 dBm

at work (rural very small airport) - 96 to -102 dBm

at lake (mostly summer cottages) -102 to -108 dBm

Measurements taken over a two month period last summer. As you can see a very
wide difference. Loop antennas at the same locations show only a few dB
variation in noise floor.

I believe you mentioned mounting an e probe on a balcony. Sounds like a real
ground connection would be fairly far away thus making the coax feedline part of
the antenna.

I cast my vote for a loop.

Jay Rusgrove, W1VD

Laurence KL1X wrote:

> Thanks Steve - Ill  have a play - I last looked at "active whips" in the
> 70's in Antarctica but I wanted a way of gettin a more transportable system
> but as you say the Loop will win....I dont think this is going to work for
> Mexico so I wont bother taking anything....then perhaps Ill just throw it in
> the luggage anyway..... If I had a remote cabin or whatever they call them
> it would have worked, but as its my honeymoon I may be a tadge busy
> elsewhere.
>
> Thanks for the info on the beacon, I await audible results!
>
> I had that annoying unresettable trip on one of the chips which, as of yet,
> have yet to determine that fault to Ive disconnected the line for the time
> being. All the inpots to the reset/trip chip are dc wise wise so....more
> work needed here but its not affecting transmissions.
>
> and oh yes getting technical stuff foreign customs is a part of my
> portfolio...playing the part of a stupid fishing man with "tackle" boxes and
> rod tubes seems to work well  (except Africa)
>
> Cheers
> Laurence
>
> >From: Steve Dove <[email protected]>
> >Reply-To: [email protected]
> >To: [email protected]
> >Subject: Re: [Lowfer] E probes .v. loops
> >Date: Thu, 11 Sep 2003 14:16:32 -0000
> >
> >Hi Laurence,
> >
> >Trust you are well.
> >
> >Bear in mind that most of the 'antenna' of an e-field probe is in fact the
> >outer of the coax
> >feeder;  under ideal circumstances where this is contained (by grounding
> >the feeder close
> >to the antenna so decoupling the rest of the feeder) there is little to
> >choose between
> >probe or loop.  With what you're intending to go and do, the loop would
> >definitely win.
> >
> >And probably be not the most bizarre thing you've tried to get past an
> >airline . . .
> >
> >         Cheers,
> >
> >                 Steve
> >
> >p.s.  propagation getting to be good enough to possibly 'hear' you, but
> >still too noisy.
> >
> >
> >
> >
> >9/11/2003 5:04:08 AM, "Laurence KL1X" <[email protected]>
> >wrote:
> >
> > >Anybody got any history of comparing, say, a 2m diameter loop compared
> >with
> > >a high up  hiZ low noise E probe (respected commercial model...)  for
> >normal
> > >residential or hotel balcony environments on say 137/185Khz? and yep I
> >know
> > >Hotels are noisey....
> > >
> >
> >
> >
> >_______________________________________________
> >From the Lowfer mailing list
> >Send messages to: [email protected]
> >To sub/unsub visit: http://mailman.qth.net/mailman/listinfo/lowfer
>
> _________________________________________________________________
> Use custom emotions -- try MSN Messenger 6.0!
> http://www.msnmessenger-download.com/tracking/reach_emoticon
>
> _______________________________________________
> >From the Lowfer mailing list
> Send messages to: [email protected]
> To sub/unsub visit: http://mailman.qth.net/mailman/listinfo/lowfer